JP3641693B2 - IC card and method of using the same - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an IC card and a method for using the same, and more particularly to a method for realizing an IC card that can be used for different reader / writers using an IC card having the same ROM.
[0002]
[Prior art]
IC cards are attracting attention as a new information recording medium that replaces magnetic cards. This IC card can record a larger amount of information than a magnetic card and has a high level of security. A reader / writer is used as a device for reading and writing data to and from the memory in the IC card. When the IC card is inserted into the reader / writer, both are electrically connected, and a reset signal is given from the reader / writer to the IC card. In response to this reset signal, the IC card returns a reset response signal to the reader / writer. Thus, a data transmission path between the two is established, and data is read from and written to the memory in the IC card. That is, when a predetermined command code is given to the IC card from the reader / writer, the command code is decoded in the IC card, and the predetermined command is executed by the CPU in the IC card. Some commands return a response after execution. In this case, a predetermined response code such as a status is returned from the IC card to the reader / writer.
[0003]
[Problems to be solved by the invention]
IC cards and reader / writers have been developed independently by each company so far. At present, the standards are defined by the ISO, but each code transmitted between the IC card and the reader / writer is defined. Each company adopts its own settings. For example, the code “4F” is used in the standard of the company A and the code “AD” is used in the standard of the company B as the code of the read command instructing to read data. Each company has different code settings. In this case, in the IC card of company A, a routine for executing a read instruction when the command code “4F” is given is prepared in the ROM. In the IC card of company B, the command code “AD” is given If so, a routine for executing a read command is prepared in the ROM. Therefore, for example, when it is desired to change the code according to the specifications of each company, there is no method other than replacing the ROM. For this reason, it is the present condition that the code used about the IC card once issued cannot be changed on the way.
[0004]
Therefore, an object of the present invention is to provide a method for realizing an IC card that can be used for different reader / writers by using an IC card having the same ROM .
[0005]
[Means for Solving the Problems]
The present invention incorporates at least three types of memory, RAM, ROM, and EEPROM, and a CPU for accessing the memory, and each routine for executing a plurality of commands is recorded in the ROM. A table recording area for recording a response table that correlates the response content generated by each routine with the response code to be sent to the outside, and when a specific response content is generated by each routine In addition, by referring to the response table, an IC card having a function of sending out a response code corresponding to the content of the generated response is prepared, and a reader / writer connected to the IC card requests Response code and response generated by each routine Of associating the response table with the content, as written in the table recording area, each routine recorded in the ROM, and a response code itself instead of writing as information indicating the contents of the response, the table in the EEPROM The reference position of the recording area is recorded so as to be compatible with different reader / writers.
[0008]
[Operation]
In the IC card according to the present invention , the response code is recorded as a table in the EEPROM, not in the ROM. And when issuing an IC card, the process of writing the response code to the table in the EEPROM is performed according to the reader / writer to be used. Therefore, even if the IC card has the same ROM, It becomes possible to cope with different reader / writers. Since the data in the EEPROM can be rewritten even after the IC card is issued, it can be reissued at any time.
[0009]
【Example】
Hereinafter, the present invention will be described based on embodiments shown in the drawings. FIG. 1 is a block diagram showing the overall configuration of an IC card 10 according to the present invention and a reader / writer 20 used therefor. The main components in the IC card 10 are a CPU 11, a RAM 12, a ROM 13, and an EEPROM 14. The CPU 11 communicates with the reader / writer 20 via an interface (not shown) and performs processing for accessing the memories 12, 13, and 14. When the IC card 10 is inserted into the housing of the reader / writer 20, the connection terminal on the IC card 10 side and the connection terminal on the reader / writer 20 side come into contact with each other and the two are electrically connected. That is, between the two, a GND line for defining a common ground potential, a VCC line for supplying power from the reader / writer to the IC card, a CLK line for supplying a clock, and an RST line for supplying a reset signal And an I / O line for transmitting data bidirectionally. Data transmission between the two is performed alternately in one direction through the I / O line.
[0010]
The CPU 11 executes various processes based on programs prepared in the ROM 13. That is, a command execution routine and a reset response routine are prepared in the ROM 13 as shown in FIG. 1, and the CPU 11 executes various processes according to these routines. The RAM 12 is used as a work area when the CPU 11 performs various processes. The EEPROM 14 is an electrically rewritable memory and is normally used as a user area. For example, in the case of an IC card used for banking business, customer address, name, deposit and withdrawal history data, etc. are written. A feature of the present invention is that various code tables are recorded in a part of the area of the EEPROM 14. That is, in the EEPROM 14, as shown in FIG. 1, a command code table, a response code table, and a reset response code table are recorded. Here, the command code table is a table associating the command code given from the reader / writer 20 with the command execution routine in the ROM 13, and the response code table is a response code generated by the command execution routine in the ROM 13. It is a table associating contents with response codes to be sent to the outside.
[0011]
Hereinafter, the meaning of these tables will be described with reference to a specific example shown in FIG. FIG. 2 shows an example of a command code table and a response code table prepared in the EEPROM, and an example of a command execution routine prepared in the ROM. In this example, both the command code and the response code are composed of 1-byte codes. In the command code table, a code “AF, 05, 7B, 7C, 86” is defined from the first byte to the fifth byte. Similarly, in the response code table, from the first byte to the fifth byte, “ 23, 6A, 6B, FE, FF "are defined. On the other hand, five routines 1 to 5 are prepared as command execution routines. Here, for example, routine 1 is an execution routine for “read command” instructing reading to the user area, routine 2 is an execution routine for “write command” instructing writing to the user area, and routine 3 is a predetermined area in the user area. One routine consists of a program for executing one command, such as an execution routine of a “delete command” for instructing deletion of a file. Each code in the first to fifth bytes of the command code table is associated with command execution routines 1 to 5, respectively.
[0012]
Consider a case where a command code “05” is given from the reader / writer 20 to the IC card 10 via the I / O line. When such a command code is received, the CPU 11 refers to the command code table in the EEPROM 14 to decode the given command code. That is, the code in the table is referred to in order from the first byte of the command code table, and an operation for finding the same code as the given code is performed. At this time, the count is performed every time the code in the table is referenced. Since the command code “05” is the same as the second byte code in the command code table, the same code is found when the count value = 2. Therefore, the CPU 11 executes a “write command” routine of the routine 2 corresponding to the count value 2. That is, the CPU 11 interprets the given command code “05” as a “write command”. Similarly, for example, when a command code “86” is given, the routine 5 corresponding to the count value 5 is executed. As described above, if a command code table is prepared in the EEPROM 14, the command code can be easily changed because rewriting can be performed at any time. For example, when a reader / writer that outputs “88” as the “write command” is used, the code “05” in the second byte of the command code table may be rewritten to “88”.
[0013]
Depending on the command, processing to return a response may be performed. For example, if the designated address is a write-protected area as a result of executing the “write command” in routine 2, it is necessary to return a response “write impossible” to the reader / writer 20. A response code corresponding to “not writable” is not prepared in the routine in the ROM. In the routine 2, as a process of returning a response “not writable”, for example, an instruction program such as “send the 4th byte code of the response code table” is described. Therefore, the CPU 11 sends the code “FE” in the fourth byte of the response code table to the reader / writer 20 as a response code “not writable”. Thus, the response code itself is not written in each routine in the ROM, and the response code itself can always be obtained by referring to the response code table. Therefore, for example, when changing the response code “not writable” to a new code, the work of rewriting the 4th byte code of the response code table may be performed.
[0014]
In the present invention, a reset response code table is prepared in the EEPROM 14 so that the code included in the reset response signal can be changed. When communication between the IC card 10 and the reader / writer 20 is started, a reset signal is given from the reader / writer 20 to the IC card 10 via the RST line as shown in the time chart of FIG. Upon receiving this reset signal, the CPU 11 executes a reset response routine in the ROM 13 and, as a result, a reset response signal is output on the I / O line. This reset response signal includes various codes for defining transmission specifications between the reader / writer 20 and the IC card 10. For example, a clock frequency, a transmission rate, CWT (Character Waiting Time: when data is transmitted one character (1 byte) at a time, after waiting for one character to be received until the next character is received), BWT ( Block Waiting Time: Transmission parameter such as waiting time until data is output as the second block from the IC card side to the same I / O line after the data is output as the first block from the reader / writer side to the I / O line. Contains the code shown. In the conventional IC card, such a code is written in the reset response routine in the ROM 13. In the present invention, such a code itself is not written in the reset response routine. For example, an instruction program such as “send number code in the reset response code table” is described. Therefore, the content of the reset response signal can be easily changed by rewriting the content of the reset response code table in the EEPROM 14.
[0015]
In this way, various codes used with the reader / writer, such as the command code, response code, and code included in the reset response signal, can be freely rewritten, so the code required by a specific reader / writer can be changed. Or the transmission conditions required by a specific reader / writer can be easily changed. Such code change has an advantage in improving the security of the IC card.
[0016]
As mentioned above, although this invention was demonstrated based on the Example shown in figure, this invention is not limited only to this Example, It can implement in a various aspect other than this. The various codes shown in the figure are arbitrary codes used for the purpose of disclosure of the invention, and are not related to codes currently in use.
[0017]
【The invention's effect】
As described above, according to the present invention, it is possible to realize an IC card that can be used for different reader / writers by using an IC card having the same ROM .
[Brief description of the drawings]
FIG. 1 is a block diagram showing a basic configuration of an IC card and a reader / writer according to the present invention.
FIG. 2 is a diagram showing an example of various tables prepared in the EEPROM of the IC card shown in FIG. 1 and each routine prepared in the ROM.
FIG. 3 is a time chart for explaining a reset operation in the IC card.
[Explanation of symbols]
10 ... IC card 11 ... CPU
12 ... RAM
13 ... ROM
14… EEPROM
20: Reader / writer

Claims (2)

An IC card containing at least three types of memory, RAM, ROM, and EEPROM, and a CPU for accessing the memory,
Within the ROM, and are recorded each routine for executing a plurality of commands, within the EEPROM, associating with said response code to be sent to the content and external responses generated by each routine Response table is recorded ,
In each of the routines recorded in the ROM, a reference position on the response table recorded in the EEPROM is recorded instead of describing the response code itself as information indicating the content of the response,
An IC having a function of sending a response code corresponding to the generated response content to the outside by referring to the response table when a specific response content is generated by each routine card. A method of using an IC card containing at least three types of memory, RAM, ROM and EEPROM, and a CPU for accessing the memory,
Each routine for executing a plurality of commands is recorded in the ROM, and a response table for associating the content of the response generated by each routine with the response code to be sent to the outside is recorded in the EEPROM. A function for sending a response code corresponding to the generated response content to the outside by referring to the response table when a specific response content is generated by each routine. Preparing an IC card with
Writing a response table associating the response code requested by the reader / writer connected to the IC card with the content of the response generated by each routine into the table recording area;
In each of the routines recorded in the ROM, the reference position of the table recording area in the EEPROM is recorded instead of describing the response code itself as information indicating the content of the response. A method of using an IC card characterized by the above.

Images